Narcissistic number
A narcissistic number in a given number base b is a number that is the sum of its own digits each raised to the power of the number of digits.
For example −
153 = 1^3 + 5^3 + 3^3 = 1+125+27 = 153
Similarly,
1 = 1^1 = 1
Approach
We will first count the number of digits using a while loop. Then with another while loop, we pick last digit of the number and add its (count) th power to a variable sum. After the loop we return a boolean checking whether the sum is equal to the number or not.
The code for this approach will be −
Example
const isNarcissistic = (num) => { let m = 1, count = 0; while(num / m > 1){ m *= 10; count++; }; let sum = 0, temp = num; while(temp){ sum += Math.pow(temp % 10, count); temp = Math.floor(temp / 10); }; return sum === num; }; console.log(isNarcissistic(153)); console.log(isNarcissistic(1634)); console.log(isNarcissistic(1433)); console.log(isNarcissistic(342));
Output
The output in the console will be −
true true false false